1. Field of the Invention
This invention relates to a surgical device for performing face-lifting using thermal radiation, and more specifically to a face-lifting device with a specialized tip design that delivers heat The invention provides a surgical device that can improve the accuracy and speed of face-lift operations. Use of the present invention controllably causes thermally related healing contraction of the target tissues thus allowing face lifting in younger patients without the removal or cutting-out of skin in properly selected patients. The use of the present invention may also aid in the performance and results of traditional face lifting involving the cutting out of skin.
2. Description of Related Art
Cutting (in surgery) will be defined as relatively cleanly breaking through similar or dissimilar tissues with minimal adjacent tissue trauma and thus little tissue stretching, tearing or ripping. Lysis (in surgery) will be defined as breaking through similar or dissimilar tissues with or without adjacent tissue trauma and may involve stretching, tearing or ripping. Depending upon the tissues lysed, the degree of stretching or tearing of lysed tissue edges may be inconsequential or may even result in a desirable benefit such as post surgical contraction. Planes of tissue are not often flat and represent the curviform intersection of dissimilar tissues and are made at least partly of fibrous tissues, either loose and spongy or firm and tough. Planes between the soft internal organs are usually loose and spongy. Planes of tissues in the face and on bones are firm and tough. Undermining will be defined as tissue separation either within or between defined tissue planes. Undermining may be by sharp (instrument) or dull (instrument) depending upon the amount of fibrous tissue binding or existing between the tissue planes to be separated. Undermining is usually performed, as is most surgery, with the intention of minimizing trauma. Sharp instrument undermining is usually performed to separate highly fibrous or collagenous tissues; however, sharp undermining suffers from the risk of penetrating adjacent tissues inadvertently because of loss of ability to follow the desired plane. Inability to follow or maintain the plane in sharp undermining is frequently due to limited visibility, difficulty xe2x80x9cfeelingxe2x80x9d the fibrous plane, or scarring (collagen fibrosis) resulting from previous trauma or surgery. Even experienced surgeons may from time to time lose the correct plane of sharp undermining; great skill is required. Blunt undermining allows a rounded, non-sharp tipped, instrument or even human finger to find the path of least resistance between tissues; once the desired plane is found by the surgeon, it is easy to maintain the plane of blunt undermining until the task is complete. Unfortunately, blunt undermining between highly fibrous tissues such as those that comprise and maintain the shape of the human face usually causes imprecise tunneling with fibrous walls of variable thickness. Dissection usually implies a deliberate and careful sorting out and identification of tissues and usually implies that some sort of undermining has been performed to isolate the desired structure(s). In face-lifting surgery, plastic surgeons have so commonly used the terms undermining and dissection interchangeably that they have become synonymous for the most part in this specific situation. Tracking means to maintain a direction of movement upon forcing a tissue-separating instrument without unpredictable movement or leaving the desired tissue plane(s). Planar tracking means to stay in the same tissue planes. Linear tracking means to move uniformly in a straight or uniformly curved path without unpredictable movement Groups of linear tracks may form a network that creates an undermined tissue plane.
Anatomical Perspective: Lysis or undermining in one dimension (linear=x) implies forming a tunnel. Lysing or undermining in 2 dimensions at any one instant forms a plane (x, y). Traditional face-lift undermining is done just under the leather (dermis) layer of the skin where dermis joins underlying fat or subcutaneous (SQ). Even deeper within the SQ fat run larger blood vessels and delicate, non-regenerating motor nerves to the muscles that give the human face motion and expression. Deep/beneath to the SQ fat reside the muscles and glands of the face. The relevant face-lift anatomy may be referenced in Micheli-Pellegrini V., Surgical Anatomy and Dynamics in Face Lifts, Facial Plastic Surgery 1992:8:1-10, Gosain A. K. et al., Surgical Anatomy of the SMAS: A Reinvestigation, Plast Reconstr Surg. 1993: 92:1254-1263 and Jost G, Lamouche G., SMAS in Rhytidectomy, Aesthetic Plast Surg. 6:69, 1982. The SQ fat differs from body location to body location. On the face, the SQ fat has many fiber-bundles (septae) carrying nerves and blood vessels. If a surgeon were to move, shove, or forwardly-push a blunt, dull-tipped, 1-inch chisel or pencil shaped device through the fat of the face where SQ abuts the dermis, the sheer thickness of the fiber bundles would likely cause slippage of the device and result in the formation of pockets or tunnels surrounded by compacted fiber bundles or septae. Proper performance of a face-lift involves breaking the septae at a proper level to avoid damaging more important structures such as blood vessels and nerves and glands.
Disadvantages of the current techniques are numerous. Face-lifting devices described in the prior art resemble undermining devices that were constructed with cutting edges that rely entirely on the skill of the surgeon to maintain control. Inadvertent lateral cutting or tissue trauma is difficult to control. In addition, speed of separation is affected to ensure accuracy by the surgeon in separating fibrous tissue planes. There are two principle locations for face lift undermining (dissection): in the more common lower facelift (cheek/neck-lift) undermining in the subcutaneous tissues is customarily performed; in the less common upper facelift (which approximates brow-lifting) undermining in the subgaleal or temporalis fascia plane is customarily performed. Use of prior art undermining devices (including scissors, sharp rhytisectors, etc) in these planes during cosmetic surgery has, at times, resulted in unwanted cutting, trauma or perforation of adjacent structures. Scissors and rhytisectors are planar cutting instruments; thus, the position of the cutting edges with respect to the surface of the face is controllable only by the surgeon estimating location, as no 3rd dimensional bulbous limitation exists. Unfortunately, scissors with 3 dimensionally xe2x80x9cbulbousxe2x80x9d, rounded tips cannot close all the way to cut target tissue. Scissors with 2 dimensionally rounded tips can close all the way to cut target tissue but may wander inadvertently between tissue planes due to the thin third dimension (thickness) of the scissors blades.
Rubin (U.S. Pat. No. 3,667,470) describes a bone shaver and grooving device that consists of a single sharp edged extension protruding perpendicular to the plane of motion of the cutting edge of the device. The extension is intended to carve and maintain a groove in rigid, immobile, bone as it is driven forward by a surgeon""s hammer. This device is impractical for lysing facial planes because the extension would severely damage blood vessels and delicate nerves. In addition, Rubin""s invention would not maintain a planar track in soft tissues. Hendel (U.S. Pat. No. 4,600,005) describes a guided osteotome for harvesting cranial bone graft that has a single cutting tip between two bulb like guides at the edges. The guides prevent the hammer driven cutting edge from penetrating the skull too deeply as the harvesting cutting edge would tend to xe2x80x9cdivexe2x80x9d deep into the skull toward brain tissue if unhindered (vertical tracking control). However, these single guides with their geometry cannot effectively compress or pass through the collagenous, fibrous tissues into recessions making for a more precise lysis of the grouped fibers and bundles.
Current face-lifting instruments that cut with other than manual energy do not address the novel concept of a xe2x80x9cprotected planexe2x80x9d during energized face-lifting dissection. Current lasers must be fired from positions outside the patient to energize tissue within the face to cut in a very imprecise fashion (See xe2x80x9cManual of Tumescent Liposculpture and Laser Cosmetic Surgeryxe2x80x9d by Cook R C and Cook K K, Lippincott, Williams, and Wilkins, Philadelphia ISBN: 0-7817-1987-9, 1999). Tissue is damaged with little control. Current electro-surgical devices for face-lift tissue energizing must be delivered through large open pockets or through the limited access and slow moving, tedious endoscopes. Farin (U.S. Pat. No. 5,776,092) describes a single tube device that can deliver laser, ultrasound or radio frequency devices to treat tissue. However, Farin""s device is not intended for separating tissue planes and is susceptible to catching, tearing or puncturing the tissue when manipulated. It would be advantageous to provide a safe technique and device for the precise application of energy to properly separate and heat facial tissue while maintaining an exact distance from the delicate surface of the skin. The ideal device achieves this function while minimizing the chances of collateral damage to vital structures such as nerves and delicate vessels. It would be additionally advantageous for the same provisions to allow for a uniform forward tracking and feel of motion of the device that provides a surgeon with instantaneous knowledge. Properly sized and placed protrusions and recessions address all of these problems in a manner not previously possible.
One of the most recent competing procedures to incompletely dissect/lyse/cut a face-lift plane is traditional or ultrasonic liposuction. Unfortunately, dissection is incomplete as the cannulas only make tunnels. The tissues between the tunnels must be cut with scissors in order to create a plane. When the scissors cuts the fiber tissues and blood vessels constituting the walls of the tunnels, bleeding and trauma occur and frequently require spot coagulation under visualization. Other severe drawbacks of the incomplete undermining that liposuction cannulas perform include the common trauma and resultant mouth droop paralysis that occurs in the hands of even prominent surgeons when the delicate and anatomically unpredictable (20% of the population) marginal mandibular branch of the facial nerve is cut. Additionally, ultrasonic cannulas become hot and can cause thermal burns called xe2x80x9cend hitsxe2x80x9d when the cannula tip is thrust against the inside of the skin as is common during the procedure.
Just as sharp undermining or dissection has its disadvantages, as previously mentioned, blunt dissection suffers from its own difficulties as well. Forcing a blunt object through tissue avoids indiscriminate sharp cutting of important structures (nerves, vessels). Blunt undermining compacts the stronger, firmer, strands of collagen even contained within tissues as soft fat into thicker xe2x80x9cbandsxe2x80x9d (some overly thick for uniform cutting). Undesirably for a face lift, traditional blunt object undermining may indiscriminately force aside and compact septae causing incomplete lysis or freeing of the tissues. Also unfortunately for face lifting, traditional purely blunt object undermining will result in random motion or uncontrollable-slippage of the underminer tip on forward motion and thusly loss of precise tracking of the underminer through target tissue.
Currently it takes surgeons between 20 minutes and one hour to carefully and properly dissect/undermine/lyse/lift a lower face. It usually takes between 10 minutes and 30 minutes, depending upon the patient to carefully and properly spot coagulate/seal all of the blood vessels that were cut during the aforementioned lysing portion of the face-lift For upper face lifting, times are less than half that mentioned for lower face lifting. The present invention would reduce time for a surgeon to do both the duties of lysing and coagulation since the device performs both tasks as well as aids in maintaining proper positioning and tracking. The time reduction should be at least 50-75%. Reduced operating time means less time a wound is open to potential infection, lowered surgical costs and less time and therefore less risk under anesthesia and thus a general improvement in the procedure.
There exists a special subset of the general population that may benefit uniquely from the present invention. Men and women between the ages of 35 and 55 are just beginning to droop and develop folds. However, there is not as much undulating wrinkling as in older patients. Currently long incisions of 10-20 cm are made around each of the two ears, for the purposes of hiding the scars. Skin is cut out and discarded and the remaining skin stretched. Unfortunately, skin does not thicken in response to stretching; it only thins. Unfortunately, some plastic surgeons in the early 1990""s advocated xe2x80x9cprophylacticxe2x80x9d or xe2x80x9cpreemptivexe2x80x9d face-lifting on women in their 40""s purportedly to xe2x80x9cstay ahead of nature.xe2x80x9d This philosophy has now been discounted and discredited by the vast majority of reputable experts. With the present invention, tightening will be most dramatic in younger patients between 35 and 55 years of age such that surgeons may not have to cut out or stretch skin for a desirable effect for most patients in this population. In this case, the present invention is inserted through only 3 relatively small incisions of less than 1 cm each and energy is applied to the upper subcutaneous, lower dermal and platysmal face-lift layers. If the 3 small incisions can be used and no skin excised, then the procedure will take less than 15 minutes following anesthesia and the effects will last for at least several years.
Given the disadvantages and deficiencies of current face-lifting techiques, a need exists for a device that provides a fast and safe alternative.
An object of the present invention is to provide a method and a device that can be used by surgeons to provide quick and accurate face-lifting maneuvers that minimize the amount of affected tissue.
It is another object of the present invention to provide an undermining device that can position lysing surfaces at a proper level for fibrous tissue lysing during a face-lift.
Another object of the invention is to provide quick and accurate face-lifting maneuvers.
Still another object of the invention is to provide a surgical face-lifting device that easily maintains the proper dissection plane.
It is a further object of the invention to provide a surgical face-lifting device that easily maintains the proper dissection plane while lysing and delivers thermal radiation to the internal collagenous tissues of the face to induce skin tightening.
Other objects of the invention will be apparent from the disclosure herein.
Thermal effects to the collagenous (dermal, superficial platysma musculature and other) tissues of the face in the facelift plane can cause cosmetically desirable contraction of the dermal tissues with beneficial tightening of the facial tissues. The present invention combines a unique lysing design with means for providing thermal radiation to efficiently lyse and
simultaneously induce the thermal contraction necessary for face lifting. The present invention may be used in hospitals as well as office-based surgery and minimizes pain and risk of injury.
The device is comprised of an undermining shaft with a special tip that can be easily positioned between dissection planes in tissue and then manipulated to separate tissue planes and lyse fibrous tissue. A thermal source and delivering means delivers energy to the distal end of the shaft A temperature sensor monitors the tissue temperature, and control electronics process temperature information to control the thermal radiation for optimum tissue contraction. An optional secondary light source that is visible to the surgeon can be used to help visualize the location of the thermal radiation exit window. Optionally the device can also use ultrasound energy or lower frequency vibrational energy delivered down the shaft to improve tissue lysing.
In one embodiment of the invention, the user sets the desired tissue temperature on an external control unit using a touch pad or other user interface. The shaft of the device is then inserted through a small (xcx9c1 cm long) incision and positioned at the desired tissue plane. For lower face lifting the surgeon incises the skin in front of the ears and under the chin. Force is then applied to the shaft of the device by the users hand to separate tissue planes while excluding critical structures (nerves, vessels) thus avoiding entanglement or trauma or indiscriminate cutting of these important structures. The same protrusions that exclude critical structures by virtue of their relationship to the recessed cutting segments also serve to position the depth of the present invention with respect to the lower dermis. The spacing of the protrusions (bulbs) and recessions (lysing segments) maintains the tracking of the instrument Tracking is instantly palpable by the surgeon and requires no monitor to know how the device is moving. Both the number and spacing of protrusions in the present invention reduce wobble or lateral (horizontal) slippage during forward thrusting of the shaft. Uniquely, vertical slippage is prohibited as well. The width of the protrusions/bulbs maintains the correct distance between the lysing segments and the delicate underside of the superficial skin or dermis. The tip of the device and the action of the device can be felt/appreciated without direct visualization (endoscope). The surgeon can palpably feet the device is tracking in the proper location. The feel of the device as it moves with palpable and easily grade-able resistance through the facial tissues can immediately tell the user-surgeon the location and the amount of undermining that has occurred at that location.
The unique tip is comprised of alternating, preferably relatively symmetrical-across-a-midline, protrusions and recessions. The protrusions can be bulbous, geometric, etc., as long as the tips of the protrusions are able to push and compress tissues into the cutting recessed segments. The recessed segments have a sharpened edge that effectively lyses the tissue that comes into contact as the device is pushed forward. The close spacing of the grooves (caused by the alternation of tip protrusions and recessions) provides the user with a feel during forced tissue movement and significantly limits slippage. Again, the tip of the device, and the action of the device can be felt/appreciated without direct visualization (endoscope).
If desired by the user, thermal radiation exits an optical window near the distal end of the shaft to heat the tissue that lies near the window. The thermal radiation propagates away from the face to effectively heat the skin layer from the inside out The purpose of the thermal energy is to alter/irritate the collagen so as to controllably cause later shrinkage and optionally to control any bleeding. The power required to coagulate such a layer of tissue is only a few watts. This flux can be provided by a thermal source such as a hot tungsten filament with temperature of about 1000 degrees. Since most preferred thermal sources are not highly visible to the human eye, the device will offer the user the option to simultaneously transmit visible light down the shaft to give the user the ability to visualize the region being treated. For example, red light that is easily transmitted through several millimeters of skin could be safely used to guide the surgeon. Thermal radiation can be controlled manually by the user or alternatively automatically controlled to prevent excessive or inappropriate thermal damage.
An alternative embodiment of the device uses a heated segment near the distal tip of the device to heat the tissue directly. The heated segment could be a thin film resistor that is heated by flowing a current through the film. The temperature of this film would be selected by the user and will typically be less than 80xc2x0 C. This embodiment eliminates the possibility of the tissue being heated above the desired temperature. In addition, the heated segment can be larger than the thermal radiation output window in previous embodiments without significant risks.
In one embodiment, the temperature of the target tissue is measured with a non-contact temperature sensor and the value displayed and used by the thermal radiation control unit to actively control the thermal radiation. The preferred temperature sensor would be an infrared temperature sensor, but other conventional sensors may be used, such as fiber optic fluorescence temperature sensors, thermal resistance sensors, and thermocouple sensors. In order to improve lysing efficiency, one embodiment of the device incorporates an ultrasound transducer into the hand piece that transmits ultrasound energy down the shaft A lower frequency vibrating transducer could also be incorporated into the device to improve lysing.
In another embodiment, the recessed cutting segments of the device are driven by an electro-surgical RF generator to improve lysing and allow RF heating of tissue.
The present invention can be used to improve the efficacy and safety of face lifting and is thus useful in a variety of cosmetic procedures. The forgoing and other objects, features, and advantages of the present invention will become apparent from the following description and accompanying drawings.
The disclosures of this publication and the disclosures of all other publications recited herein are incorporated by reference as if fully set forth herein. Co-pending U.S. patent applications Ser. Nos. 09/478,172 and 09/475,635 are incorporated herein by reference.